ab is a tool for benchmarking the performance of your WWW HyperText Transfer Protocol (HTTP) server. It does this by giving you an indication of how many requests per second your Apache installation can serve.
Options
-A auth-username:password
Supply BASIC Authentication credentials to the server. The username and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the server needs it (i.e., has sent an 401 authentication needed).
-b windowsize
Size of TCP send/receive buffer, in bytes.
-c concurrency
Number of multiple requests to perform at a time. Default is one request at a time.
-C cookie-name=value
Add a Cookie: line to the request. The argument is typically in the form of a name=value pair. This field is repeatable.
-d
Do not display the "percentage served within XX [ms] table". (legacy support).
-e csv-file
Write a Comma separated value (CSV) file which contains for each percentage (from 1% to 100%) the time (in milliseconds) it took to serve that percentage of the requests. This is usually more useful than the ‘gnuplot’ file; as the results are already ‘binned’.
-f protocol
Specify SSL/TLS protocol (SSL2, SSL3, TLS1, or ALL).
-g gnuplot-file
Write all measured values out as a ‘gnuplot’ or TSV (Tab separate values) file. This file can easily be imported into packages like Gnuplot, IDL, Mathematica, Igor or even Excel. The labels are on the first line of the file.
-h
Display usage information.
-H custom-header
Append extra headers to the request. The argument is typically in the form of a valid header line, containing a colon-separated field-value pair (i.e., "Accept-Enooding: zip/zop;8bit").
-i
Do head requests instead of GET.
-k
Enable the HTTP KeepAlive feature, i.e., perform multiple requests within one HTTP session. Default is no KeepAlive.
-n requests
Number of requests to perform for the benchmarking session. The default is to just perform a single request which usually leads to non-representative benchmarking results.
-p POST-file
File containing data to POST. Remember to also set -T.
-P proxy-auth-username:password
Supply BASIC Authentication credentials to a proxy en-route. The username and password are separated by a single : and sent on the wire base64 encoded. The string is sent regardless of whether the proxy needs it (i.e., has sent an 407 proxy authentication needed).
-q
When processing more than 150 requests, ab outputs a progress count on stderr every 10% or 100 requests or so. The -q flag will suppress these messages.
-r
Don’t exit on socket receive errors.
-s
When compiled in (ab -h will show you) use the SSL protected https rather than the http protocol. This feature is experimental and very rudimentary. You probably do not want to use it.
-S
Do not display the median and standard deviation values, nor display the warning/error messages when the average and median are more than one or two times the standard deviation apart. And default to the min/avg/max values. (legacy support).
-t timelimit
Maximum number of seconds to spend for benchmarking. This implies a -n 50000 internally. Use this to benchmark the server within a fixed total amount of time. Per default there is no timelimit.
-T content-type
Content-type header to use for POST data, eg. application/x-www-form-urlencoded. Default: text/plain.
-v verbosity
Set verbosity level – 4 and above prints information on headers, 3 and above prints response codes (404, 200, etc.), 2 and above prints warnings and info.
-V
Display version number and exit.
-w
Print out results in HTML tables. Default table is two columns wide, with a white background.
-x <table>-attributes
String to use as attributes for <table>. Attributes are inserted <table here >.
-X proxy[:port]
Use a proxy server for the requests.
-y <tr>-attributes
String to use as attributes for <tr>.
-z <td>-attributes
String to use as attributes for <td>.
-Z ciphersuite
Specify SSL/TLS cipher suite (See openssl ciphers).
Test Result
#ab -n 20 -c 10 -t 60 http://www.localhost.com/
Benchmarking www.localhost.com (be patient)
Finished 154 requests
Server Software: Apache/2.2.3
Server Hostname: www.localhost.com
Server Port: 80
Document Path: /
Document Length: 56611 bytes
Concurrency Level: 10
Time taken for tests: 60.5793 seconds
Complete requests: 154
Failed requests: 0
Write errors: 0
Total transferred: 8933962 bytes
HTML transferred: 8906422 bytes
Requests per second: 2.57 [#/sec] (mean)
Time per request: 3896.480 [ms] (mean)
Time per request: 389.648 [ms] (mean, across all concurrent requests)
Transfer rate: 145.39 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 257 610 1192.0 258 9256
Processing: 1037 2848 2052.2 2076 13469
Waiting: 258 454 872.4 259 10038
Total: 1296 3459 2368.4 2591 14335
Percentage of the requests served within a certain time (ms)
50% 2591
66% 3892
75% 4672
80% 5163
90% 6588
95% 7761
98% 9361
99% 13729
100% 14335 (longest request)
